Substrate for liquid crystal display device including peripheral lines having openings and fabricating method thereof

ABSTRACT

A liquid crystal display device includes a substrate having a display region and a non-display region. In the display region, the gate line and a data line cross to define a pixel region and a thin film transistor is disposed at the crossing portion of the gate and data lines. The thin film transistor includes a gate electrode and source and drain electrodes. A peripheral line having a plurality of openings is disposed in the non-display region. The openings are slits, rectangles, circles, or triangles. The openings relieve plasma during dry-etching of the peripheral line. A pixel electrode is connected to the drain electrode in the pixel region.

The present patent document is a divisional of U.S. patent applicationSer. No. 11/144,269, filed Jun. 3, 2005, which claims priority to KoreanPatent Application No. 10-2004-0040301 filed in Korea on Jun. 3, 2004.

BACKGROUND

1. Field of the Invention

The present invention relates to a liquid crystal display device, andmore particularly, to a substrate for a liquid crystal display (LCD)device and a fabricating method thereof.

2. Discussion of the Related Art

Until recently, display devices have typically used cathode-ray tubes(CRTs). Presently, much effort is being expended to study and developvarious types of flat panel displays, such as liquid crystal display(LCD) devices, plasma display panels (PDPs), field emission displays,and electro-luminescence displays (ELDs), as a substitute for CRTs. Ofthese flat panel displays, the LCD devices have many advantages, such ashigh resolution, light weight, thin profile, compact size, and lowvoltage power supply requirements.

In general, an LCD device includes two substrates that are spaced apartand face each other with a liquid crystal material interposed betweenthe two substrates. The two substrates include electrodes that face eachother such that a voltage applied between the electrodes induces anelectric field across the liquid crystal material. Alignment of theliquid crystal molecules in the liquid crystal material changes inaccordance with the intensity of the induced electric field intodirection of the induced electric field, thereby changing the lighttransmissivity of the LCD device. Thus, the LCD device displays imagesby varying the intensity of the induced electric field.

FIG. 1 is a perspective view of a LCD device according to the relatedart. FIG. 2 is a schematic view of structures of a peripheral line on asubstrate for an LCD device according to the related art.

As shown in FIG. 1, the LCD device 9 includes a first substrate 10, asecond substrate 20 and a liquid crystal material 18. The secondsubstrate 20 is referred to as a color filter substrate that includes acolor filter pattern 24, a black matrix 22 between the color filterpatterns 24, and a common electrode 28 on both the color filter pattern24 and the black matrix 22. The first substrate 10 is referred to as anarray substrate that includes a data line 14 and a gate line 12 thatcross each other and define a pixel region P. A pixel electrode 16 and athin film transistor T as a switching element are positioned in eachpixel region P. Thin film transistors T, which are disposed adjacent towhere the data lines 14 and the gate lines 12 cross, are disposed in amatrix form on the first substrate 10. A data pad electrode 15 isdisposed on one end of the data line 14. Thought not shown in FIG. 1, agate pad electrode is disposed on one end of the gate line 12.

To fabricate the related art LCD device, multiple mask processes areconducted, for example, a five-mask method or a four-mask method.

A five-mask method includes a first mask process for forming the gateline 12 and a gate electrode of the thin film transistor T, a secondmask process for forming a semiconductor pattern of the thin filmtransistor T, a third mask process for forming the data line 14 andsource and drain electrodes of the thin film transistor T, a fourth maskprocess for forming a passivation layer, and a fifth mask process forforming a pixel electrode 16. The first to fifth mask processes areconducted with a wet-etching, method or a dry-etching method.

When the five-mask method is used, a peripheral line 80, as shown inFIG. 2, including a common line, a ground line and so on is formedduring the first to third processes. The peripheral line 80 is formed ina non-display region ND defined at peripheral portions of a displayregion D having the pixel regions P. The peripheral line 80 has largerarea than the data line 14 such that a resistance thereof is reduced. Inthe five-mask method, since each layer is patterned with eachcorresponding mask process, the patterned layer is not affected bydifferent mask processes. However, to decrease production process timeand cost, the number of mask processes used is reduced.

The four-mask method includes four mask processes. The four-mask methodincludes a first mask process for forming the gate line 12 and a gateelectrode, a second mask process for forming the data line 14, sourceand drain electrodes and a semiconductor pattern therebelow, a thirdmask process for forming a passivation layer, and a fourth mask processfor forming the pixel electrode 16. The first to fourth mask processesare conducted with a wet-etching method or a dry-etching method.

When the four-mask method is used, the peripheral line 80 is formedduring the first and second processes. The second mask process isconducted to pattern not only the data line 14 and the source and drainelectrodes, but also the semiconductor pattern therebelow. In otherwords, the data line 14 and the source and drain electrodes, and thesemiconductor pattern therebelow are patterned with the same maskprocess. Accordingly, etching times for the second mask processincrease. Further, when the dry-etching method for the second maskprocess is used, the amount of etching gases used increase. Therefore,the peripheral line 80 at the same layer as the data line 14 isover-etched during the second mask process, and thus portions of theperipheral line 80 may be etched away. Further, since the peripheralline 80 has a large area to reduce the resistance thereof, plasmagenerated for the dry-etching method is concentrated on the peripheralline 80. Therefore, the peripheral line 80 is further over-etched, andthus portions of the peripheral line 80 may be etched away. As a result,the resistance of the peripheral line 80 is changed, and thus displayquality of the LCD device is degraded.

BRIEF SUMMARY

A substrate for a liquid crystal display device is provided that canreduce over-etching of a peripheral line and improve display quality. Inaddition, a method of fabricating a substrate for a liquid crystaldisplay device is provided that can reduce over-etching of a peripheralline and improve display quality.

By way of introduction only, a display device includes a substratehaving a display region and a non-display region; a gate line and a dataline to define a pixel region in the display region; a thin filmtransistor at the crossing portion of the gate and data lines, the thinfilm transistor including a gate electrode and source and drainelectrodes; a peripheral line having a plurality of openings in thenon-display region; and a pixel electrode connected to the drainelectrode in the pixel region.

In another aspect, a method of fabricating a display device includesforming a gate line and a gate electrode on a substrate, the substratehaving a display region and a non-display region; forming first andsecond semiconductor layers, a data line, source and drain electrodesand a peripheral line, wherein the data line crosses the gate line todefine a pixel region in the display region, and the peripheral line hasa plurality of openings in the non-display region; and forming a pixelelectrode connected to the drain electrode in the pixel region.

In another aspect, a method of fabricating a display device includes:forming a metal layer in a non-display region of a substrate; forming aphotoresist on the metal layer; patterning the photoresist to form aphotoresist pattern on the metal layer; and etching the metal layerusing the photoresist pattern to form a peripheral line having aplurality of openings. The display device may be fabricated using nomore than four mask processes.

Accordingly, the openings may be of sufficient size and number torelieve concentration of plasma during dry-etching of the peripheralline such that no portions of the peripheral line are etched away duringthe dry-etching of the peripheral line.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention. In the drawings:

FIG. 1 is a perspective view of a LCD device according to the relatedart;

FIG. 2 is a schematic view of structures of a peripheral line on asubstrate for an LCD device according to the related art;

FIG. 3 is a plan view of a substrate for an LCD device according to thepresent invention;

FIG. 4 is a schematic view of structures of a peripheral line on asubstrate for an LCD device according to the present invention. Thesubstrate for the LCD device is fabricated with a four-mask method;

FIGS. 5A to 5C are schematic views of openings for a peripheral linehaving rectangular, circular and triangular shapes, respectively,according to the present invention;

FIGS. 6A, 7A, 8A, 9A, 10A, 11A, 12A and 13A are cross sectional viewstaken along a line of FIG. 3 of a fabricating method of a substrate foran LCD device according to the present invention;

FIGS. 6B, 7B, 8B, 9B, 10B, 11B, 12B and 13B are cross sectional viewstaken along a line IV-IV of FIG. 3 of a fabricating method of asubstrate for an LCD device according to the present invention;

FIGS. 6C, 7C, 8C, 9C, 10C, 11C, 12C and 13C are cross sectional viewstaken along a line V-V of FIG. 3 of a fabricating method according of asubstrate for an LCD device to the present invention; and

FIGS. 6D, 7D, 8D, 9D, 10D, 11D, 12D and 13D are cross sectional viewstaken along a line VI-VI of FIG. 3 of a fabricating method of asubstrate for an LCD device according to the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS AND THE PRESENTLY PREFERREDEMBODIMENTS

Reference will now be made in detail to the illustrated embodiments ofthe present invention, which are illustrated in the accompanyingdrawings.

FIG. 3 is a plan view of a substrate for an LCD device according to thepresent invention. FIG. 4 is a schematic view of structures of aperipheral line on a substrate for an LCD device according to thepresent invention. The substrate for the LCD device is fabricated with afour-mask method.

As shown in FIG. 3, a gate line 202 and a data line 224 are disposed ona substrate 200 having a display region D and a non-display region ND atperiphery portions of the display region D. The gate and data lines 202and 224 cross each other to define a pixel region P in the displayregion D. A gate pad electrode 206 is disposed on one end of the gateline 202, and a data pad electrode 238 is disposed on one end of thedata line 224. The gate pad and data pad electrodes 206 and 238 isdisposed in the non-display region ND. A gate pad electrode terminal 256and a data pad electrode terminal 258 are disposed on the gate and datapad electrodes 206 and 238.

A thin film transistor T is disposed at the crossing portion of the gateand data lines 202 and 224. The thin film transistor T includes a gateelectrode 204, a first semiconductor pattern 213 a, and source and drainelectrodes 220 and 222. A second semiconductor pattern 213 b is disposedbelow the data line 224 and extended along the data line 224.

A pixel electrode 254 is disposed in the pixel region P and connected tothe drain electrode 222. A storage electrode 226 is disposed on the gateline 202 to define a storage capacitor C_(ST) with the gate line 202overlapping the storage electrode 226. The storage electrode 226 isconnected to the pixel electrode 254. A third semiconductor pattern 213c is disposed below the storage electrode 226.

Since the substrate for the LCD device of the present invention isfabricated with a four-mask method, the second and third semiconductorpatterns 213 b and 213 c are formed below the data line 224 and thestorage electrode 226. Further, the semiconductor patterns 213 a to 213c have widths greater than the source and drain electrodes 220 and 222,the data line 224 and the storage electrode 226.

In the non-display region ND, a peripheral line 240 including a commonline and a ground line is disposed as shown in FIG. 4. The peripheralline 240 has larger area than the data line 224 such that a resistancethereof is reduced. According to the four-mask method, the fourthsemiconductor pattern is disposed below the peripheral line 224similarly to the first to third semiconductor patterns 213 a to 213 c.The peripheral line 240 has a slit-shaped opening 241 to relieve plasmafor a dry-etching method being concentrated on the peripheral line 240.In other words, since the peripheral line 240 has slit-shaped openings241 which are arranged in parallel to each other at the side portions,the peripheral line 240 has an area smaller than that of the relatedart. Accordingly, concentration of plasma for the dry-etching method maybe relieved. It should be understood that the slit-shaped opening 241 isdisposed inside the peripheral line 240 to reduce the area thereof. Toreduce the area of the peripheral line 240, other shaped openings may beused.

FIGS. 5A to 5C are schematic views of openings for a peripheral linehaving rectangular, circular and triangular shapes, respectively,according to the present invention.

As shown in FIG. 5A, an opening 241 of a peripheral line 240 may have arectangular shape. The rectangular-shaped openings 241 may be arrangeduniformly in the peripheral line 240. Further, as shown in FIG. 5B, anopening 241 of a peripheral line 240 may have a circular shape. Thecircular-shaped openings 241 may be arranged uniformly in the peripheralline 240. Further, as shown in FIG. 5C, an opening 241 of a peripheralline 240 may have a triangular shape. The triangular-shaped openings 241may be arranged uniformly in the peripheral line 240.

As above explained, the opening 241 of the peripheral line 240 has slit,rectangular, circular and triangular shapes. However, it should beunderstood that the opening 241 may have other shapes to reduce the areaof the peripheral line 240.

FIGS. 6A, 7A, 8A, 9A, 10A, 11A, 12A and 13A are cross sectional viewstaken along a line III-III of FIG. 3 of a fabricating method of asubstrate for an LCD device according to the present invention. FIGS.6B, 7B, 8B, 9B, 10B, 11B, 12B and 13B are cross sectional views takenalong a line IV-IV of FIG. 3 of a fabricating method of a substrate foran LCD device according to the present invention. FIGS. 6C, 7C, 8C, 9C,10C, 11C, 12C and 13C are cross sectional views taken along a line V-Vof FIG. 3 of a fabricating method according of a substrate for an LCDdevice to the present invention. FIGS. 6D, 7D, 8D, 9D, 10D, 11D, 12D and13D are cross sectional views taken along a line VI-VI of FIG. 3 of afabricating method of a substrate for an LCD device according to thepresent invention.

As shown in FIGS. 6A to 6D, a first metal layer is deposited on asubstrate 200 having a pixel region P, a switching region T, a dataregion DR, a storage region ST, gate and data pad regions GP and DP, anda peripheral region SD. The pixel region P, the switching region S andthe storage region ST are defined in the display region D (in FIG. 4),while the gate and data pad regions GP and DP, and the peripheral regionSD are defined in the non-display region ND (in FIG. 4). The first metallayer is patterned with a first mask process to form a gate line 202, agate electrode 204 and a gate pad electrode 206. The gate pad electrode206 is formed in the gate pad region GP. The first metal may be at leastone of aluminum (Al), aluminum alloy (AlNd), copper (Cu), tungsten (W),chromium (Cr) and molybdenum (Mo).

Subsequently, a gate insulator 208 is formed entirely on the substrate200 having the gate line 202. The gate insulator 208 may be made of aninorganic insulating material including silicon nitride (SiNx) andsilicon oxide (SiO₂).

Subsequently, an intrinsic amorphous silicon (a-Si:H) layer 210 and animpurity-doped amorphous silicon (n+a-Si:H) layer 212 are sequentiallydeposited on the gate insulator 208. A second metal layer 214 isdeposited on the impurity-doped amorphous silicon layer 212. The secondmetal layer 214 may be at least one of aluminum (Al), aluminum alloy(AlNd), copper (Cu), tungsten (W), titanium (Ti), chromium (Cr) andmolybdenum (Mo).

Subsequently, as shown in FIGS. 7A to 7D, a photoresist layer 216 isdeposited on the second metal layer 214 to conduct a second maskprocess. A second mask M is disposed over the photoresist 216. Thesecond mask M includes a transmission portion A1, a shielding portion A2and a semi-transmission portion A3. Through the second mask M, thephotoresist 216 is exposed to a light. When the photoresist layer 216uses a positive type resist which exposed to the light is developed, thesemi-transmission portion A3 corresponds to the gate electrode 204, theshielding portion A2 corresponds to the storage region ST, the dataregion DR and the data pad region DP. Further, the transmission andshielding portions A1 and A2 are arranged alternately in the peripheralregion SD to form a slit-shaped opening. Other-shape openings, as shownin FIGS. 5A to 5C, may be formed in a way similar to forming theslit-shaped opening according to changing suitably the transmission andshielding portions A1 and A2 corresponding to the peripheral region SD.

A light-exposure process is conducted with the second mask M, and then adeveloping process is conducted. Accordingly, the photoresist layer 216is developed, and thus first and second photoresist patterns 218 a and218 b are formed on the second metal layer 214, as shown in FIGS. 8A to8D. The first photoresist pattern 218 a is formed corresponding to theswitching region T, and the second photoresist pattern 218 b is formedcorresponding to the storage region ST, the data pad region DP and theperipheral region SD. In particular, portions of the first photoresistpattern 218 a corresponding to the semi-transmission portion A3 (in FIG.7A) has a height smaller than other portions of the second photoresistpattern 218 b corresponding to the shielding portion A2 (in FIG. 7A),due to the light transmittance difference. The second photoresistpattern 218 b corresponding to the peripheral region SD has a pluralityof holes apart form each other exposing the second metal layer 214.

Subsequently, through the first and second photoresist patterns 218 aand 218 b, a first etching process for the second metal layer 214, theimpurity-doped amorphous silicon layer 212 and the intrinsic amorphoussilicon layer 210 is conducted. The first etching process may use adry-etching method for the three layers, or both a wet-etching methodfor the second metal layer 214 and a dry-etching method for theimpurity-doped amorphous silicon layer 212 and the intrinsic amorphoussilicon layer 210.

Through the first etching process, as shown in FIGS. 9A to 9D,source-drain electrode pattern 215 in the switching region T, a dataline 224 in the data region DR, a data pad electrode 238 in the data padregion DP, a storage electrode 226 in the storage region ST, and aperipheral line 240 having an opening 241 in the peripheral region SDare formed. The opening 241 exposes the gate insulator 208. Further,first, second, third and fourth semiconductor patterns 213 a, 213 b, 213c and 213 d having the same shape in plane as the source-drain electrodepattern 215, the data line 224 and the data pad electrode 238, thestorage electrode 226 and the peripheral line 240, respectively, areformed. Each of the first, second, third and fourth semiconductorpatterns 213 a, 213 b, 213 c and 213 d includes the patternedimpurity-doped silicon layer 222 and the patterned intrinsic amorphoussilicon layer 210. In particular, the patterned intrinsic amorphoussilicon layer 210 and the patterned impurity-doped amorphous siliconlayer 212 of the first pattern semiconductor pattern 213 a are referredto as an active layer and an ohmic contact layer, respectively.

Subsequently, as shown in FIGS. 10A to 10D, an ashing process for thefirst and second photoresist patterns 218 a and 218 b is conducted. Theashing process is conducted until portions of the first photoresistpattern 218 a corresponding to the semi-transmission portion A3 (in FIG.7A) are removed to expose the source-drain electrode pattern 215. Whenthe ashing process conducted, upper portions and side portions of thefirst and second photoresist patterns 218 a and 218 b are partiallyremoved. Accordingly, heights of the first and second photoresistpatterns 218 a and 218 b are reduced, and side portions F of thesource-drain electrode pattern 215, the data line 224 and the data padelectrode 238, the storage electrode 226 and the peripheral line 240 areexposed through the ashed photoresist patterns 218 a and 218 b.

Subsequently, a second etching process is conducted with the ashedphotoresist patterns 218 a and 218 b, and thus the exposed portions ofthe source-drain electrode pattern 215 and the side portions F of thesource-drain electrode pattern 215, the data line 224 and the data padelectrode 238, the storage electrode 226 and the peripheral line 240 areremoved. Accordingly, as shown in FIGS. 11A to 11D, source and drainelectrodes 220 and 222 apart from each other in the switching region T.Then, the ashed photoresist patterns 218 a and 218 b (in FIGS. 10A to10D) are stripped.

Subsequently, the patterned impurity-doped silicon layer 212 of thefirst semiconductor pattern 213 a is etched with the source and drainelectrodes 220 and 222 as an etching mask to form a channel CHcorresponding to the gate electrode 204. Further, side portions of thepatterned impurity-doped amorphous silicon layer 212 of the first tofourth semiconductor patterns 213 a to 213 d are removed with the sourceand drain electrodes 220 and 222, the data line 224, the data padelectrode 238, the storage electrode 226 and the peripheral line 240 asan etching mask.

The semiconductor patterns 213 a to 213 d have widths greater than thesource and drain electrodes 220 and 222, the data line 224, the data padelectrode 238, the storage electrode 226, and the peripheral line 240,due to the second etching process.

Subsequently, as shown in FIGS. 12A to 12D, a passivation layer 242 isformed entirely on the substrate 200 having the data line 224. Thepassivation layer 242 may be formed of an inorganic insulating materialincluding silicon nitride (SiNx) and silicon oxide (SiO₂), or an organicinsulating material including benzo-cyclo-butene (BCB) and acrylic. Witha third mask process, first, second, third and fourth contact holes 246,248, 250 and 252 are formed. The first, second and fourth contact holes246, 248 and 252 are formed with etching the passivation layer 242, andthus the first, second and fourth contact holes 246, 248 and 252 exposethe drain electrode 222, the storage electrode 226 and the data padelectrode 238. The third contact hole 250 is formed with etching thepassivation layer 242 and the gate insulator 208, and thus the thirdcontact hole 250 exposes the gate pad electrode 206.

Subsequently, as shown in FIGS. 13A to 13D, a transparent conductivematerial is deposited on the passivation layer 242, and is patternedwith a fourth mask process to form a pixel electrode 254, a gate padelectrode terminal 256 and a data pad electrode terminal 258. The pixelelectrode 254 contacts the drain electrode 222 and the storage electrode226 through the first and second contact holes 246 and 248 (in FIG.12A), respectively. The gate pad electrode terminal 256 contacts thegate pad electrode 206 through the third contact hole 250 (in FIG. 12B).The data pad electrode terminal 258 contacts the data pad electrode 238through the fourth contact hole 252 (in FIG. 12C). The transparentconductive material may include indium-tin-oxide (ITO) andindium-zinc-oxide (IZO).

Through the above explained processes, the substrate for the LCD deviceof the present invention is fabricated. In the substrate for the LCD,the peripheral line having a large area to reduce the resistance thereofhas openings to reduce the area of the peripheral line. Accordingly, theconcentration of plasma generated for the dry-etching method on theperipheral line can be reduced, and thus over-etching thereof can bereduced. Therefore, the resistance of the peripheral line can beuniform, and thus display quality of the LCD device can be improved.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the substrate for the LCDdevice and the method of fabricating the substrate for the LCD device ofthe present invention without departing from the spirit or scope of theinvention. Thus, it is intended that the present invention cover themodifications and variations of this invention provided they come withinthe scope of the appended claims and their equivalents.

The invention claimed is:
 1. A method of fabricating a display device,the method comprising: forming a gate line and a gate electrode on asubstrate, the substrate having a display region and a non-displayregion; forming first and second semiconductor layers, a data line,source and drain electrodes and a peripheral line, wherein the data linecrosses the gate line to define a pixel region in the display region,and the peripheral line has a plurality of openings in the non-displayregion; forming a passivation layer on the peripheral line in thenon-display region; and forming a pixel electrode connected to the drainelectrode in the pixel region, wherein the second semiconductor layerextends along and below the peripheral line, and the passivation layerdirectly contacts the second semiconductor layer, etching a metal layerin an etching process to form a source-drain electrode pattern, the dataline, and the peripheral line, and etching the plurality of openings inthe peripheral line in the same etching process, and wherein when thepassivation layer is applied on the data line and the peripheral line,the passivation layer fills in the openings of the peripheral line. 2.The method according to claim 1, wherein the openings have at least oneof slit, rectangular, circular or triangular shapes.
 3. The methodaccording to claim 1, wherein the peripheral line includes a common lineand a ground line.
 4. The method according to claim 1, furthercomprising forming a gate insulator on the gate electrode, wherein thegate electrode is connected to the gate line, and the secondsemiconductor layer is formed on the gate insulating layer.
 5. Themethod according to claim 4, wherein the gate insulator is exposedthrough the openings.
 6. The method according to claim 1, furthercomprising forming a third semiconductor layer below the data line. 7.The method according to claim 1, further comprising forming a thirdsemiconductor layer and a storage electrode on the third semiconductorlayer overlapping the gate line.
 8. The method according to claim 1,further comprising forming a gate pad electrode at one end of the gateline, and forming a third semiconductor pattern and a data pad electrodeon the third semiconductor pattern at one end of the data line.
 9. Themethod according to claim 1, further comprising forming a gate padelectrode terminal on the gate pad electrode, and forming a data padelectrode terminal on the data pad electrode.
 10. The method accordingto claim 1, wherein widths of the first and second semiconductor layersare larger than the source and drain electrodes, and the peripheralline.
 11. The method according to claim 6, wherein a width of the thirdsemiconductor layers is larger than the data line.
 12. The methodaccording to claim 1, wherein the first and second semiconductor layershave same shapes as the source and drain electrodes, and the peripheralline.
 13. The method according to claim 6, wherein the thirdsemiconductor layer has a same shape as the data line.
 14. The methodaccording to claim 1, wherein each of the first and second semiconductorlayers includes at least one of an intrinsic amorphous silicon layer oran impurity-doped amorphous silicon layer.
 15. The method according toclaim 6, wherein the third semiconductor layer includes at least one ofan intrinsic amorphous silicon layer or an impurity-doped amorphoussilicon layer.
 16. The method according to claim 11, wherein thepassivation layer is between the drain electrode and the pixelelectrode, and the passivation layer has a contact hole contacting thedrain electrode and the pixel electrode.
 17. The method according toclaim 1, wherein forming the first and second semiconductor layers, thedata line, the source and drain electrodes and the peripheral lineincludes: forming a semiconductor layer, a metal layer and a photoresistlayer on the substrate; exposing the photoresist layer with a maskhaving transmission, semi-transmission and shielding portions, thetransmission and shielding portions arranged alternately in thenon-display region to form a first photoresist pattern having aplurality of holes; and etching the semiconductor layer and the metallayer with the first photoresist pattern to form the peripheral line andthe second semiconductor layer having the plurality of openingscorresponding to the plurality of holes.
 18. The method according toclaim 17, wherein the semiconductor layer and the metal layer are etchedusing a dry-etching method.
 19. The method according to claim 17,wherein the semiconductor layer and the metal layer are etched using adry-etching method and a wet-etching method.
 20. The method according toclaim 17, further comprising forming a second photoresist patternincluding portion having a height smaller other portions thereof, thesmaller-height portion corresponding to the semi-transmission portion,and etching the semiconductor layer and the metal layer with the secondphotoresist pattern to form the data line, the source and drainelectrodes, and the first semiconductor layer.
 21. The method accordingto claim 20, wherein etching the semiconductor layer and the metal layerincludes: etching the semiconductor layer and the metal layer with thefirst and second photoresist patterns to form the data line, asource-drain electrode pattern, the peripheral line, and the first andsecond semiconductor layers; etching an exposed portion of thesource-drain electrode patterns with the first and second photoresistpattern to form the source and drain electrodes; and etching the firstand second semiconductor layers with the data line, the source and drainelectrodes, and the peripheral line.
 22. The method according to claim21, further comprising ashing the first and second photoresist patternto remove the smaller-height portion of the first photoresist pattern toexpose portion of the source-drain electrode pattern after etching thesemiconductor layer and the metal layer.
 23. The method according toclaim 21, wherein the semiconductor layer includes at least one of anintrinsic amorphous silicon layer or an impurity-doped amorphous siliconlayer.
 24. The method according to claim 23, wherein the impurity-dopedamorphous silicon layer of the first and second semiconductor layers isetched with the data line, the source and drain electrodes, and theperipheral line.
 25. A method of fabricating a display device, themethod comprising: forming an insulator in both a display region and anon-display region of a substrate; forming a first semiconductor layeron the insulator; forming a second semiconductor layer on the firstsemiconductor layer; forming a metal layer on the second semiconductorlayer and in the non-display region; forming a photoresist on the metallayer; patterning the photoresist to form a photoresist pattern on themetal layer; and etching the metal layer and the first and secondsemiconductor layers using the photoresist pattern to form a data lineand a peripheral line, a plurality of openings are etched through theperipheral line in the same etching process, wherein the insulator isexposed through the plurality of openings; and forming a passivationlayer on the peripheral line and the data line and directly contacting aside surface of the first semiconductor layer and the insulator throughthe plurality of openings, and the passivation layer filling in theplurality of openings.
 26. The method according to claim 25, wherein theopenings are of sufficient size and number to relieve concentration ofplasma during dry-etching of the peripheral line such that no portionsof the peripheral line are etched away during the dry-etching of theperipheral line.
 27. The method according to claim 26, wherein theopenings have at least one of slit, rectangular, circular or triangularshapes.
 28. The method according to claim 25, wherein the display deviceis fabricated using no more than four mask processes.
 29. The methodaccording to claim 25, further comprising ashing the photoresist patternto expose a portion of the peripheral line.
 30. The method according toclaim 29, further comprising etching the peripheral line exposed by theashing.
 31. The method according to claim 30, further comprising etchingat least one of the first and second semiconductor layers under theperipheral line exposed by the ashing in the same etching process asetching the peripheral line exposed by the ashing.